Paracelsus is naming something that stops before God — or rather, something God works upon rather than authors. The prima materia is not a creature; it is what creation requires. That distinction sounds scholastic until you feel what it implies: there is a substrate prior to all making that no act of making can account for, something uncreated running underneath the created world, filling the aethereal region, mothering the elements without itself being one of them.

The alchemists kept reaching for this because they sensed that transformation — real transformation, not refinement — has to start somewhere that is not already formed. You cannot remake what is already finished. The prima materia is their name for the unfinished, the radical root of the thing before it became the thing. Jung returned to this obsessively in his alchemy work because the psyche also has such a substrate: not the ego, not the persona, not even the complex, but whatever underlies them that is not itself a product of experience.

What Paracelsus adds, and what makes the passage strange, is the irreversibility. This unique material will never return to what it was; nothing future will resemble it. The mother of the elements is herself unrepeatable. That is not a mystical flourish — it is a warning about the kind of attention the prima materia demands. It cannot be reconstructed from its products.